Pickup trucks typically include a tailgate or end gate that, when opened, is 30 or more inches above the ground upon which the vehicle is parked. In many instances, it is difficult for an individual to climb into and out of the vehicle bed. Existing foldable and storable step structures for vehicles and, more specifically, pickup trucks are inadequate as they do not support enough weight and/or are too cumbersome when stored. In particular, many existing ladder assemblies do not provide clearance for bed covers and camper shells. Accordingly, a need exists for an improved ladder assembly for a tailgate of a truck.